JPS6021805B2 - Punch for ironing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a punch for ironing the body of a drawn and ironed can, and more specifically, to a punch for ironing the body of a can which has been drawn and ironed, and which facilitates the extraction of the body of a can after drawing and ironing and which has excellent ironing formability. Regarding processing punches.

BACKGROUND ART Drawn and ironed can bodies conventionally used for carbonated beverage cans, beer cans, etc. are manufactured, for example, in the following manner.

A cup-shaped molded body formed by drawing from tin-plated steel plate or aluminum alloy plate, etc.
After being redrawn and ironed by the ironing device shown in FIG. 1, the can body is extracted from the punch and sent to the next process. In FIG. 1, 1, 2, 3 are ring dies for ironing, and 4 are ironing punches. The molded product is drawn into a cup shape by a re-drawing die (not shown) and punch 4 located on the left side of FIG. Aperture with reduced width and increased length -
It is formed in the ironing can body 5. During this time, lubricant coolant 6 is jetted out from nozzle 7 for lubrication and cooling. Next, punch 4
In the return process in the direction of the arrow, the closed end surface 5a of the can body 5 and the tip 9a of the claw 9 of the stripper 8 engage (
1), the can body 5 is extracted from the punch 4.

The stripper 8 in FIG. 1 shows a stripper with a simple structure, and has a plurality of claws 9 surrounding the punch 4.
It also includes a ring-shaped elastic body 10 for pressing the tip end 9a of the claw 9 in the radial direction. Open end 5b of can body 5
The thickness is usually about 0.150 to 0.175, and 8
It is thicker than the thickness of the main wall 5c (usually about 0.100 to 0.11 mm), and in order to form the can body in this way, the diameter of the punch 4 is slightly increased toward the left side of the figure. A shoulder portion 4a is provided which is tapered to become thinner. This is to prevent the end 5b of the flange from breaking. Care has been taken to provide the punch 4 with an air inlet hole 4b to prevent the formation of a vacuum at the bottom of the can body and the bottom view of the punch. Since the body wall portion of the body 5 is normally configured as described above, it is often difficult to extract the can body, and buckling may occur in the vicinity of the extraction point and the closed end 5b, resulting in a defective can body. , or the can body may be carried to the die section without being extracted, causing trouble in which the device may be destroyed. Even if extraction is carried out without causing the above-mentioned troubles, there is a problem in that the distal end 9a of the claw 9 wears out due to the large extraction resistance and must be replaced frequently. The present invention aims to solve the above problem by improving the punch.

The ironing formability is improved if the side peripheral surface of the ironing punch is narrow to some extent (that is, even if the ironing rate is increased, the can body is less likely to break or the bottom edge is less likely to be undulated). Focusing on this, ironing punches having a rough side peripheral surface are disclosed in Jitsuki Sho 49-38733 and Tokusei Sho 49-90668. However, in this case, it becomes more difficult to extract the can body from the punch, as described in Jitsekki Sho 49 Ichikan No. 733. Therefore, in Jitsoseki Sho 49-38733, a punch for ironing is proposed whose finished surface has a cut of 0.8 French or less and whose outer shape is an inverted conical shape. This is not preferable because it imposes certain restrictions on the shape of the can body and thus the can product. Therefore, usually a punch whose entire side surface is lapped smoothly is used, placing more emphasis on the ease of extracting the can body than on the ability to form the can body. However, even in this case, the ease of extraction is not necessarily good, and depending on the structure of the stripper, the type of lubricating coolant used, etc., problems such as buckling as described above may occur. The present invention has been made in view of the problems of conventional ironing punches as described above, and the object of the present invention is to facilitate the extraction of ironed can bodies and to provide excellent ironing formability. Our objective is to provide a punch for ironing.

The present invention will be described below with reference to drawings showing embodiments.

In FIGS. 2 and 3, 4a is the shoulder of the punch 4, 4c is the main part of the punch side surface corresponding to the trunk wall main part 5c of the can body, and 4d is the main part of the punch side corresponding to the mouth end 5M of the can body. The side surface of the punch 4 is formed by the side surface of the side king portion 4c, the shoulder portion 4a, and the folded portion 4d.

The side main portion 4c has a right cylindrical shape and is not tapered. A groove line portion 11 is formed in the side surface main portion 4c, which is substantially continuous in a spiral shape and extends substantially in the circumferential direction. A smooth portion 12 is formed between each groove line portion. Latitude section 11
As shown in FIG. 3, the cross section is V-shaped, and its depth is preferably about 0.5 to 5 mm, more preferably about 1 to 5 mm. Groove line capital 11 serves as a reservoir for lubricating coolant and plays an important role in lubricating the can body from which it is extracted, but if its depth is shallower than about 0.5 mounds On the other hand, even if the depth is deeper than about 5 mounds, the function as a reservoir does not particularly improve, and therefore, the extractability is not particularly improved, but rather the reprocessing becomes more difficult. This is because the problem of increasing the finishing allowance of the insert and shortening the final life of the punch arises. This depth does not need to be uniform over the entire surface of the side main portion 4c, and is about 0.5
It may vary within the range of ~5〆wind. Groove line part 11
must extend approximately in the circumferential direction, and the average interval in the punch axis direction (in the case of a spiral, the pitch) is approximately 0.05 to 2. It is preferable that the ratio is about 0.1 to about 1.5. These reasons can be considered as follows. FIG. 4 schematically shows the state in which the can body 5 is ironed using the punch 4 of the present invention, and the die 1 (or 2, 3 ,) A low protrusion 13a having a shape substantially corresponding to the shape of the entrance portion of the groove line portion 11 is formed at a position corresponding to the groove line portion 11 on the inner surface near the entrance portion.

When the ironing process starts, a part of the inner surface of the main body part 5c is moved to the latitude line part 11 due to the strong compressive force from the die 1.
This is because it is press-fitted into the In the portions where the ironing process has further progressed, the protrusions are press-fitted into the groove line portions 11 more deeply as 13b and 13c because they receive a stronger compressive force from the die 1. Therefore, the incompressible lubricating coolant 6 that has accumulated in the groove line portion tends to be pushed out. In this case, groove line part 1
1 extends approximately in the circumferential direction, the lubricating coolant 6 has an escape place only between the punch smooth part 12 near the groove line part 11 and the body wall main part 5c, and therefore it cannot enter into this place. A thin layer 6' of lubricant is formed. When the groove line portions 11 are spiral-shaped, they are mutually compatible, so it is thought that the lubricating coolant can escape through the spiral grooves. However, for example, if the punch diameter is 5mm and the spiral pitch is 0.2mm, the speed required to escape is about 80 pm, which is the ironing speed, and the lubricating coolant has a certain viscosity. It is considered that due to such factors, a considerable amount of the lubricant coolant cannot escape and forms the lubricant layer 6' as described above. Due to the presence of this lubricant layer 6', the punch 4 and the main body part 5c do not stick to the stripper 8 when the stripper 8 is used to remove the material, thereby reducing the amount of extraction force, that is, the force at the beginning of extraction. It is assumed that
However, if the groove line has a relatively large angle with respect to the circumferential direction, for example, in an extreme case, the groove line 11' is parallel to the axial direction of the punch 4' as shown in Fig. 5. The straining state can be considered as shown in Figure 6. In other words, although some lubricant coolant may accumulate, as the ironing progresses, the lubricant coolant 6 can easily escape from the groove line 11' in the direction of the arrow to the left in the figure, forming the lubricant layer as described above. 6' is not formed. Therefore, the effect of reducing the extraction force is considered to be poor. FIG. 7 schematically shows a state in which the can body with the inner protrusion 13 formed thereon is pulled out from the punch 4 (the body wall main part 5c is stopped and the punch is in the direction of the arrow). direction).
8 The wall main capital 5c is very thin as mentioned above (usually about 0.
100 to 0.110 side), and is flexible, so it can be easily expanded to the extent that the bottom surface 13× of the protrusion 13 can be stretched over the surface of the smooth portion 12.

However, some resistance occurs when the protrusion 13 is pulled out from the groove line portion 11. Moreover, even if the protrusion 13 is pulled out once due to its elastic restoring force, it will repeatedly fall into the next groove line part 11 and be pulled out again. The force required to pull out the can body based on this resistance increases as the number of groove line portions 11 increases, that is, as the average distance between the groove line portions 11 decreases, and according to the experience of the present inventors, the above-mentioned average distance is approximately This is because if it is smaller than the 0.05 side, it becomes quite difficult to pull out the can body. In the drawing process, the lubricating coolant 6 and the lubricant layer 6' sealed in the groove line portion 11 coat the surface of the smooth portion 12, and have the effect of reducing the sliding resistance of the projection portion 13. On the other hand, when the average spacing is larger than about 2 sails, the number of groove lines 11 in the longitudinal direction of the punch decreases, and therefore the amount of lubricating coolant sealed decreases, and furthermore, the length of the smooth section increases. As a result, lubrication of the smooth surface becomes insufficient, and
This is because the rope resistance of the protrusion 13 increases, making it difficult to remove the can body. Since the groove line portion 11 has a V-shaped cross section, the protruding portion 13 also has a correspondingly substantially V-shaped cross section as described above.

Therefore, when the punch 4 is extracted from the can body 5, the inclined surfaces 1, la of the latitude line portion 11 extending approximately in the circumferential direction can be moved relatively easily along the inclined surface 13y while pushing out the protruding portion 13 in contact therewith. can slide out. Therefore, combined with the above-mentioned lubrication effect, extraction becomes easy. In this case, as in the example shown in FIG. 3, if the slope of the mirror slope with respect to the direction of the sea bream is gentle, it will be easier for the sea bream to slip out.

In addition, in Fig. 3, the above slope seems steep at first glance, but the vertical magnification of the figure is 10 tones of the horizontal magnification, so
The actual slope is very gentle. On the other hand, the cross section of the groove line part is
In the case of a letter-shaped or rectangular shape, the protrusion also has a substantially U-shaped or rectangular cross section, and the groove line portion and the radially extending surfaces of the protrusion come into contact with each other.

When the punch 4 is extracted, the punch 4 tries to move in the axial direction, but since the two surfaces are engaged with each other in a direction perpendicular to the extraction direction, it is difficult to slide along each other. Therefore, extraction becomes difficult. Groove line section inverted V
If you make it into a letter shape, the above-mentioned engagement will become even stronger, so
It becomes even more difficult to remove the punch. Centerline average roughness of smooth portion 12 (according to JISB0601).

In this specification, the average roughness (referred to as average roughness) is desirably 0.05 or less. This is because if the average roughness is greater than 0.05 rm, the frictional resistance between the protrusions 13 and the smooth portion will increase, making it difficult to pull out the can body. Note that there is no problem even if a few groove lines having a pitch of 0.5 or less are mixed in the smooth portion 12. Also, the boundary 1 between the smooth portion 12 and the groove line portion 11
4 preferably has a gentle roundness. This is to reduce the resistance as much as possible when the protrusion 13 is pulled out from the groove line portion. Groove line part 11 is usually the side center of punch 4c
It is only necessary to provide it on the shoulder portion 4a and the folded portion 4d.

As described above, a spiral groove line portion is formed on the side surface,
A punch having a smooth portion between the groove line portions is manufactured, for example, in the following manner.

The outer wall of the ironing punch is usually made of cemented carbide, and after polishing the side surface with a fine-grained grindstone, the entire surface is lapped smoothly with diamond powder having a diameter of about 5 mm.

Next, use a bamboo spatula or Bakelite spatula (or a "spatula" made of an equivalent material) with a lapping agent made by semi-mixing approximately 100 μm of yomogi diamond powder with oil. Then, a spatula J made of a material with appropriate strength is pressed against the side surface of the rotating punch and gradually moved in the direction of the punch axis to form a spiral groove line. After the above finishing is completed, The roundness of the smooth part and the boundary between the smooth part and the groove line part is formed by lapping with another bamboo spatula or Bakelite spatula coated with about 5 rm of flea diamond powder. Can 8 shaped by pressing with a punch like this
This figure shows the shape of the inner surface of the trunk wall main part 5c of the body 5, in which a spiral protrusion 13 is formed. The height of the protrusion 13 is usually about 1.0 mm, and the width of its base is about 0.0 mm.
The presence of such irregularities on the 05 side has the effect of increasing the adhesion of the coating film applied to the inner surface by spraying. FIG. 10 shows the surface profile of a punch according to another embodiment of the present invention, in which the depth of each groove line portion 11 and the mutual spacing are uneven compared to the case of FIG. Further, the groove line portion 11 is discontinuous.

In this case as well, the depth and spacing of the groove lines 11 and the smooth portion 12
Since the average roughness of the can body exceeds the above-mentioned desirable conditions, the can body can be easily extracted. This kind of surface condition is
For example, it can be obtained by polishing with a coarse grindstone of about 20 flea to form a groove line, and then lapping it using diamond powder with a diameter of about 1 to 5 ridges as described above to form a smooth part. can. However, in this case, the loss of punch diameter (polishing allowance) in one polishing operation is 20 to 30 mm, whereas in the first embodiment (spiral groove line part Compared to the case of 1), since there is a limit to the amount by which the punch diameter can be reduced, there is a disadvantage that the life of the punch is shorter.

The ironing punch of the present invention has a smooth surface and a groove line part, and the groove line part serves as a reservoir for lubricant, and at the same time, a protrusion is formed on the inner surface of the can body for ironing.

This is because a lubricant layer is formed on the smooth part of the can body where the protrusion is formed, but if the can body wall is thin and flexible, it is easier to remove the can body than with the stripper. When pulled out, the protrusion easily slides onto the smooth surface. moreover,
Because of the protrusion, the contact area between the inner surface of the can body and the punch surface is small, and the lubricant in the reservoir is supplied from the protrusion surface to the smooth part, which facilitates the above-mentioned sliding. On the other hand, with a punch whose entire surface is smooth, the contact area between the inner surface of the can body and the surface of the punch is much larger than in the case of the present invention, and there is no lubricant reservoir, so contact There is also very little lubricant on the surface. Therefore, when using the punch of the present invention, it is much easier to extract the can body than when using a conventional smooth punch. Furthermore, since it suppresses slippage on the inner surface of the can body during ironing of the groove line, it has the effect of superior ironing formability compared to conventional smooth punches. It goes without saying that the punch of the present invention has better extraction properties than the conventional rough-surfaced punch. A specific example will be explained below.

Specific example Side main part 4c (right cylindrical shape) diameter 52.65 side, height 1
15 ribs, shoulder height 9.5 side, reduced part diameter 52.52
After polishing the side circumferential surface of an ironing punch with a hardened alloy sleeve with 65 ribs in height using a 100% soundproof whetstone, it was lapped smoothly using diamond powder with a roughness of about 5 ridges.
While rotating the punch, press a bamboo spatula coated with diamond powder (oil paste) with a diameter of about 100 ridges on the side main part 4c and gradually move it in the direction of the wisteria line to form a spiral groove line, and then, The main part 4c of the side surface is finished by lapping again with diamond powder of approximately 5 degrees of roughness to obtain the surface profile shown in Fig. 3 (
A punch having a Tokyo Seimitsu ■ stylus-type assembly tester (measured on Surfcom 40 ship) on the side main part 4c was manufactured.

Photomicrograph (magnification: 100) of the surface of the lateral main capital 4c is shown in the 11th photo.
Shown in the figure. The black line extending in the vertical direction is the groove line portion. Next, a molded body made by squeezing a tin-plated steel plate with a thickness of 0.32 mm and a tin coating amount of 5.6 mm/metre (both sides) into a cup shape, using the punch described above, Re-drawing and ironing was performed using an ironing machine.

In this case, the first scrubbing rate is 38.2%, the second scrubbing rate is 13.6%, and the third scrubbing rate is 39.4%, and a water emulsion of mineral oil is used as the lubricating coolant. used. A strain gauge was attached to the punch mounting shaft, and the force for extracting the ironed can body (maximum value, extraction speed 0.08/sec) was determined to be 220 kg.

On the other hand, for comparison, a lap smooth finishing punch (
The ironing process was carried out under the same conditions as above, except that the ironing process was carried out under the same conditions as above, and the extraction force was determined to be 284k9.
Met. In a practical test, the replacement life of the stripper claw 9 in the case of the punch of the present invention was approximately three times that of the replacement life of the stripper claw in the case of using the smoothly wrapped punch of the comparative example.

[Brief explanation of drawings]

Fig. 1 is a schematic longitudinal cross-sectional view of the ironing device; Fig. 2 is a front view of a punch for ironing according to an embodiment of the present invention;
The figure is a diagram showing the surface profile of the side surface of the punch in Figure 2, and Figure 4 is a schematic enlarged vertical cross-sectional view of the main part to explain the behavior of ironing using the punch in Figure 2. , FIG. 5 is a front view of an example of a punch that does not belong to the present invention, and FIG.
The figure is a schematic enlarged vertical cross-sectional view of the main part to explain the behavior of the iron when ironing is performed using the punch shown in Figure 5, and Figure 7 is an enlarged longitudinal cross-sectional view of the main part of the iron when ironing is performed using the punch shown in Figure 2. Figure 8 is an enlarged vertical cross-sectional view of the main parts of the iron can body to explain the state of the punch for extracting the can body. , FIG. 9 is a diagram showing the surface profile of the inner surface of the main part of the can body of FIG. 8, and FIG.
The figure is a bran diagram showing the surface profile of the side surface of a punch according to another embodiment of the present invention, and FIG. 11 is an enlarged microscopic photograph of the main surface of the side surface of the punch of the type shown in FIG. 4...Punch for ironing, 5...Drawing - ironing can body, 11...Groove line portion, 12...
... Smooth part, 14... Boundary between groove line part and smooth part. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Bandits/Sardines

Claims (1)

[Claims] 1. Drawing - Ironing In a punch for ironing for forming a can body, most of the side surface of the punch in contact with the inner surface of the body wall of the can body has a smooth portion with an average roughness of 0.05 μm or less and a depth of 0.05 μm or less. It consists of a groove line portion with a V-shaped cross section of approximately 0.5 to 5 μm and extending approximately in the circumferential direction, and the groove line portion has a diameter of approximately 0.5 μm.
A punch for ironing, characterized in that they are formed at an average interval of 0.5 to 2.0 mm, and the boundary between the smooth portion and the groove line portion is rounded.